FIG. 26 illustrates a publicly-known axle bearing device for a railway vehicle. An axle bearing device 200 illustrated in FIG. 26 includes: a roller bearing 210; a front lid 202 and a rear lid 203 provided respectively on both sides in an axial direction of the roller bearing 210 while sandwiching therebetween inner rings 211 of the roller bearing 210 in the axial direction; and sealing devices 220 and 220 arranged respectively at opening portions at one end and another end of the roller bearing 210. The roller bearing 210 is what is called a double row tapered roller bearing, and includes the inner rings 211 fixed to an axle 201 of a railway vehicle, an outer ring 212 fixed to a journal box (not shown) of the railway vehicle, tapered rollers 213 as rolling elements arranged in double rows between raceway surfaces of the inner rings 211 and the outer ring 212, and retainers 214 for retaining the tapered rollers 213 at predetermined intervals in a circumferential direction.
The sealing device 220 arranged on a proximal end side of the axle 201 includes an outer-ring-side sealing member formed of a sealing case 221 fixed to an inner periphery of an end portion of the outer ring 212 and a sealing member 222 fixed to an inner periphery of the sealing case 221, and the rear lid 203. Specifically, as illustrated in an enlarged part in FIG. 26, an opening portion between the inner ring 211 and the outer ring 212 is sealed by a contact seal formed by bringing sealing lips 222a and 222b provided at an inner diameter end portion of the sealing member 222 into contact with an outer surface of the rear lid 203, and a non-contact seal (labyrinth seal) formed by fitting a leading end 221a of the sealing case 221 to an annular groove 203a provided in an end surface of the rear lid 203 across a gap. The sealing device 220 arranged on a leading end side of the axle 201 has substantially the same structure. With this, leakage of lubricant such as grease filling an inner space of the roller bearing 210 (annular space formed between the inner ring 211 and the outer ring 212) to an outside, and intrusion of foreign matter such as dust into a bearing inner space are prevented as much as possible (for details, refer, for example, to Patent Literatures 1 and 2).